Two-high rolling stand

ABSTRACT

A rolling stand for hot or cold rolling of bar steel or wire rod stock comprises first and second rolls which define a nip therebetween. The first and second rolls have surface portions which engage the stock and reduce its cross section as the stock advances therebetween. The first and second rolls also have drive-transmitting surface portions which engage each other and which are spaced axially from the stock-engaging surface portions. A means is provided for establishing a drivetransmitting relationship between the drive-transmitting surface portions of the rolls so that the second roll is driven from the first roll by the drive-transmitting surface portions.

United States Patent [191 Bennet et al.

[451 July 23, 1974 TWO-HIGH ROLLING STAND [75] Inventors: Tom JoachimBennet; Knut Lennart Nordstroem; Karl 010i Polhaell, all

of Smedjebacken, Sweden [73] Assignee: Morgardshammer Aktiebolag,

Smedjebacken, Sweden [22] Filed: Nov. 17, 1972 [21] Appl. No.: 307,353

[30] Foreign Application Priority Data Nov. 17, 1971 Sweden....-[4690/71 52 US. Cl. 72/249, 72/245 [51] Int. Cl B21b 35/00 [58] Field ofSearch 72/249, 245; 100/176 [56] References Cited I UNITED STATESPATENTS 1,147,713 7/1915 Fox 72/234 7 3,124,982 3/1964 Neumann.... 72/213,559,432

2/1971 Rastelli 72/19 3,566,638 3/l97l Herbst 72/8 FOREIGN PATENTS ORAPPLICATIONS 54,014 2/1922 Sweden 72/249 373,441 4/1923 Germany 72/249Primary Examiner-Milton S. Mehr 5 7 ABSTRACT A rolling stand for hot orcold rolling of bar steel or wire rod stock comprises first and secondrolls which define a nip therebetween. The first and second rolls havesurface portions which engage the stock and reduce its cross section asthe stock advances therebetransmitting surface portions of the rolls sothat the second roll is driven from the first roll by the drivetransmitting surface portions.

9 Claims, 3 Drawing Figures PATENIEM TWO-HIGH ROLLING STAND BACKGROUNDOF THE INvENTIoN The present invention relates to a rolling stand, andparticularly a rolling stand for hot or coldrollingof bar steel or wirerod stock.

Conventionally, rolling stands forhot or cold rolling of bar steelor'wire rod stock comprises a pair of rolls which have surface portionswhich engage the stock to reduce the cross section of the stock as thestock advances therebetween. As thestock advances between the rolls, thestock tends to cause the rolls to spread or separate. Such conventionalrolling stands have provision for'applying a force to the rolls toprevent such rolls from separating and to effect the desired stock crosssection reduction. y

In the past, .such rolling stands have utilized separate drives for eachrollQCommonly, each roll is'driven through a universal joint by eitherexternal gearing or by separate directly coupled motors. Such driving ofeach roll separately requires a large machine invest-. mentand requiresa substantial amount of space in the mill area. Y

' There are known equipment constructions having a pair of rolls whichdefine a rliptherebetween through which stock is advanced. In such knownconstructions,

only one of the'rolls is driven, the other roll being driven by theengagement with the stock during advancement of the stock between therolls. However, there is no known rolling stand in which only one of therolls is driven. 'In all known rolling stands, there have been separatedrives utilized for each roll, as noted hereinabove.

SUMMARY OF TI-IE PRESENTINVENTION The present invention is directed to-arolling stand and method of rolling in which separate drives, as notedabove, are eliminated. This, of course, reduces the investment cost withrespect to the'construction of the stand and also minimizes spacerequirements.

The present invention specifically provides a rolling stand having apair of'stock-shaping rolls where only one of the rolls of the rollingstand'is driven by an input drive, the other roll being driven throughtorquetransmitting drive surfaces of the rolls. More specifically, eachof the rolls has a drive-transmitting surface which is engageable with adrive-transmitting surface on the other roll. While one of the rolls isdriven, the other roll is driven from or due to the engagement of thedrive-transmittingsurfaces.

In accordance with the present invention, a drivetransmittingrelationship is established betweeen the surface portions of the rollsby a suitable means which urges the rolls together with a force inexcess of the force necessary to effect the rolling of the stock, andsufficiently in excess to provide the drive. This means which appliesthe force to the drive-transmitting surfaces of the rolls is such thatthe force may be removed when rolling is not being effected so as torelieve the pressure forces on the surfaces of the rolls, thereby pro-'DESCRIPTION OF THE DRAWINGS Further features and advantages of thepresent invention will be apparent to those skilled in the art to whichit relates from the following detailed description of a preferredembodiment thereof made with reference to the accompanying drawings Ishowing one of the embodiments of theinvention and in which:

FIG. 1 is a schematic front view of a rolling stand embodying thepresent invention;

FIG. 2 is a sectional view taken approximately along the line II--II inFIG. '1; and

FIG. 3 shows an enlarged view of an improved groove shape which may beapplied to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention, as notedabove, provides an improved and unique roll stand. The present inventionis applicable to avariety of roll stand constructions,

and as representative isillustrated in the drawings as applied to a rollstand A. The roll stand A is a two-high roll stand andv comprisestwopairsof rollerbearing housings l. The roll stand also includes a pair ofrolls 2 and 3. The rolls 2, 3 have shaft portions which project stock 7,which is advanced between the rolls, is shaped as it moves through the'nip. In fact, the rolls have surface portions 2a and 3a which define agroove through which the stock moves. The surface portions 2a, 3a,

engage the stock as it advances between the rolls and effect a reductionin the cross section of the stock as it advances therebetween.

The'roll 3 is positively driven bya suitable external drive which isgenerally designated by the reference numeral 8. The drive 8 may be ofany suitable form, such as either gearing or an independent motor, andthe reference numeral 8 represents the drive shaft for driving the roll3. It should be apparent from the drawings that there, is no externaldrive, 'such as an independent motor or gearing, for driving the roll 2.In accordance with the present invention, the roll 2 is driven from theroll 3 due to frictional engagement between drivetransmitting surfaceportions on the rolls 2, 3.

More specifically, the roll 2 is driven due to the'fact that the surfaceportions 6 thereof are in a drivetransmitting relationship withcorresponding surface portions'6 on the r0113. The surface portions 6,when stock is being rolled, are in a sufficient pressure relationship toeffect the transmission of torque therebetween so that the roll 22 ispositively driven at the surface speed of the roll 3 through thosesurface portions.

Suitable means is provided in the rolling stand A for effecting thedrive-transmitting relationship between the surface portions 6 of therolls. That means, as disclosed in FIG. 2, is designated B. The means Bfor establishing the drive-transmitting pressure relationshipspecifically includes a pair of screw rods 4 which extend slidablythrough passageways in the roller bearing housings 1. The lower rollerbearing housing 1, as illustrated in FIG. 3, has recesses 10 therein forreceiving the head end of the rods 4. The upper roller bearing housing 1has chamber portions therein through which the rods 4 extend and whichchamber portions are divided into two chambers by piston members 5. Thetwo chambers are designated 11 and 12 in FIG. 2.

The chambers 11 and 12 are suitably connected to a hydraulic system forreceiving hydraulic fluid from that system. It should be apparent that,when there is an equal fluid pressure in the chambers 11 and 12, theonly force applied between the rolls 2 and 3 is that due to the weightof the roll 2 and the bearing. If a higher pressure is applied in thechamber portion 11 than in chamber 12, there is an upward force actingon the upper roller bearing housing 1, tending to cause the rollerbearing housing 1 to raise. This, of course, causes a reduction in theforce applied through the surface portions 6 of the rolls 2 and 3; Infact, the pressure in chamber 11 can be relatively high enough so as toeliminate all forces applied between the rolls 2, 3 and, specifically,between the surface portions 6 thereof. Moreover, when the roll stand isnot in operation, the rolls can be moved completely apart'to provide-agap between the surface por'tions 6.

It should also'be apparent from the above that in the event the pressurein chamber portion 12 exceeds that in chamber portion 11 the rollerbearing housings 1 are forced together. Whenthe roller bearing housingsl are forced together, the roll surface portions 6 come into contact anddepending upon the relative pressures in the chamber portions 11, 12,the force'urging the rolls together is controlled. Accordingly, therelative pressures in chamber portions ll, 12 control the force withwhich the rolls are engaged. That force, of course,

is controlled so asto provide a sufficient force urging the rollstogether to overcome the force of the stock tending to separate therolls and also sufficient to provide the drive-transmitting relationshipbetween the surface portions 6 of the rolls 2 and 3, so that the roll 2is driven solely by that pressure relationship between the surfaceportions 6 of the rolls 2 and 3.

The drawings illustrate the mechanisms B for applying the force andreleasing the force on the right side of the rolls 2, 3, but it shouldbe clear that a similar mechanism is applied .to and associated with theroller bearing housings 1 onthe left side of the rolls, so that in allthere are four screw rods 4 and four sets of hydraulic chambers '11, 12for controlling the pressure applied to the rolls 2 and 3.

From the above, it should be apparent that applicants have provided ahighly improved roll stand which is extremely simple in construction,since it requires only one drive into the roll stand for driving one oftherolls and that the second roll is driven by a drivetransmittingsurface engagement with thedriven roll. Also, the pressure relationshipbetween the drivetransmitting surfaces of the rolls can be controlled byhydraulics, and when the roll stand is idle, the rolls can be completelyseparated in order to eliminate any force being applied between thesurfaces of the rolls. This, of course, forms a gap between thedrive-transmitting surface portions 6, which is of great advantage as itallows for possible removal of finished stock which may be between therolls.

Illustrated in FIG 3 is a specific roll construction capable of use inthe roll stand embodying the present in vention. As illustrated in FIG.3, the rolls define a groove 9 which is provided with an extra gap whichextends axially outwardly'of the groove 9 in opposite di- 4- rections,that gap being designated 10 in the drawings. The drive-transmittingportions between the rolls are designated8 in FIG. 3. The gap 10prevents or minimizes the possibility of slag or scales formed byreduction or rolling of the stock in the groove 9 to be urged betweenthe drive-transmitting portions 8. In other words, the groove 10provides an-area that may receive the slag or scales rather than theslag or scales tending to separate the rolls, as would be the case ifthe slag or scales tended to creep into or between the drivetransmittingsurface portions 8.

Having described our invention, we claim:

1. A rolling stand for hot or cold rolling-of bar steel or wire rodstock comprising means for reducing a dimension of the rod stockcomprising first and second rolls which define a nip therebetween, saidfirst and second rolls having surface portions which engage the stockand reduce its cross section as the stock advances therebetween, saidfirstand second rolls having further surface portions which engage eachother and which are spaced axially from the stock engaging surfaceportions, drive means for driving one of said rolls, means for applyinga pressure forcebetween said further surface portions for establishing atorque-transmitting relationship between said further surface portionsto drivesaid second roll from said first roll due to saidtorque-transmitting relationship while the rod stock is advanced betweenthe rolls and reduced thereby in dimension, means for controlling themagnitude of said pressure force, said pressure force controlling meansreducing the pressure force when there is not stock between the rollsand thereby reducing the possibility of excessive wear or cracking ofthe rolls.

2. A rolling stand as defined in claim 1 wherein each of said rolls haveshaft portions projecting from the opposite ends thereof, roller bearinghousings associated with each shaft portion and receiving each of saidshaft portions, and said means for establishing a torquetransmittingrelationship between said further surface portions comprises meansassociated with said roller bearing housings for urging said housingstogether.

3. A rolling stand as defined in claim 2 wherein said means forestablishing said torque-transmitting relationship comprises rod meanswhich extends through passages in said roller bearing housings and whichis slidably received in said passages, and hydraulic means associatedwith said rod means, said hydraulic means including first and secondchamber portions and an increase in pressure in said first chamberportion relative to the pressure in said second chamber portioneffecting movement of said roller bearing housings apart to thereby movesaid rolls apart and an increase in pressure in said second chamberportion relative to the pressure in said first chamber portion urgingsaid rolls together and increasing the pressure relationship betweensaid torque-transmitting surfaces of the rolls.

4. A rolling stand as defined in claim 1 wherein said first and secondrollshave surface portions which engage the stock to reduce the crosssection of the stock and intermediate those surface portions and thetorque-transmitting surface portions have surface portions which definea slag-receiving groove.

5. A rolling stand for hot or cold rolling of bar steel or wire rodstock comprising means for reducing a dimension of the rod stockcomprising first and second rolls which define a nip therebetween, saidfirst and second rolls having surface portions which engage the stockand reduce its cross section as the stock advances therebetween, first,drive means drivingly connected with said first roll to effect rotationthereof, and second drive means for driving said second roll, saidsecond drive means solely comprising drive-transmitting surface portionsof said first and second rolls which have a drive-transmitting pressurerelationship during rolling of the stock, means for establishing saiddrivetransmitting pressure relationship comprising means for applying apressure force urging said drivetransmitting surface portions intocontact while the rod stock is advanced between the rolls and reducedthereby in dimension, means for controlling the magnitude of saidpressure force, said pressure force controlling means reducing thepressure force when there is no stock between the rolls and therebyreducing the possibility of excessive wear and cracking of the rolls.

6. A rolling stand as defined in claim 5 wherein each of said rolls hasshaft portions projecting from the opposite ends thereof, roller bearinghousings associated with each shaft portion and receiving each of saidshaft portions, and said means for establishing a torquetransmittingrelationship between said further surface portions comprising meansassociated with said roller bearing housings for urging said housingstogether.

7. A rolling stand as defined in claim 6wherein said means forestablishing said torque-transmitting relationship comprises rod meanswhich extends through passages in said roller bearing housings and whichis.

slidably received in said passages, and hydraulic means associated withsaid rod means, said hydraulic means including first and second chamberportions, said first chamber portion on an increase in pressure thereinrelative to the pressure in said second chamber portion effectingmovement of said roller bearing housing apart to thereby move saidrollers apart and said second chamber portion upon a pressure increaserelative to the pressure in said first chamber portion therein urgingsaid rollers together to increase the pressure relationship between saidtorque-transmitting surfaces of the rollers.

8. A method of rolling bar steel or wire rod stock comprising the stepsof providing first and second rolls which define a nip therebetween,advancing stock between surface portions of the rolls to reduce thecross section of the stock, positively driving one of said rolls from anexternal source, driving the other of said rolls due to surface pressureengagement between said rolls establishing said torque-transmittingpressure relationship between said rolls to drive the second roll fromthe first roll due only to said torque-transmitting relationship whilethe rod stock is being advanced through the rolls, and reducing saidtorque-transmitting pressure when there is no stock between the rolls.

9. A method of rolling as defined in claim 8 further including the stepof varying the pressure relationship between the rolls for differentrolling operations, and removing the pressure relationship entirely andmoving one of said rolls relative to the other of the rolls when therolling operation is completed. if

1. A rolling stand for hOt or cold rolling of bar steel or wire rodstock comprising means for reducing a dimension of the rod stockcomprising first and second rolls which define a nip therebetween, saidfirst and second rolls having surface portions which engage the stockand reduce its cross section as the stock advances therebetween, saidfirst and second rolls having further surface portions which engage eachother and which are spaced axially from the stock-engaging surfaceportions, drive means for driving one of said rolls, means for applyinga pressure force between said further surface portions for establishinga torquetransmitting relationship between said further surface portionsto drive said second roll from said first roll due to saidtorque-transmitting relationship while the rod stock is advanced betweenthe rolls and reduced thereby in dimension, means for controlling themagnitude of said pressure force, said pressure force controlling meansreducing the pressure force when there is not stock between the rollsand thereby reducing the possibility of excessive wear or cracking ofthe rolls.
 2. A rolling stand as defined in claim 1 wherein each of saidrolls have shaft portions projecting from the opposite ends thereof,roller bearing housings associated with each shaft portion and receivingeach of said shaft portions, and said means for establishing atorque-transmitting relationship between said further surface portionscomprises means associated with said roller bearing housings for urgingsaid housings together.
 3. A rolling stand as defined in claim 2 whereinsaid means for establishing said torque-transmitting relationshipcomprises rod means which extends through passages in said rollerbearing housings and which is slidably received in said passages, andhydraulic means associated with said rod means, said hydraulic meansincluding first and second chamber portions and an increase in pressurein said first chamber portion relative to the pressure in said secondchamber portion effecting movement of said roller bearing housings apartto thereby move said rolls apart and an increase in pressure in saidsecond chamber portion relative to the pressure in said first chamberportion urging said rolls together and increasing the pressurerelationship between said torque-transmitting surfaces of the rolls. 4.A rolling stand as defined in claim 1 wherein said first and secondrolls have surface portions which engage the stock to reduce the crosssection of the stock and intermediate those surface portions and thetorque-transmitting surface portions have surface portions which definea slag-receiving groove.
 5. A rolling stand for hot or cold rolling ofbar steel or wire rod stock comprising means for reducing a dimension ofthe rod stock comprising first and second rolls which define a niptherebetween, said first and second rolls having surface portions whichengage the stock and reduce its cross section as the stock advancestherebetween, first drive means drivingly connected with said first rollto effect rotation thereof, and second drive means for driving saidsecond roll, said second drive means solely comprisingdrive-transmitting surface portions of said first and second rolls whichhave a drive-transmitting pressure relationship during rolling of thestock, means for establishing said drive-transmitting pressurerelationship comprising means for applying a pressure force urging saiddrive-transmitting surface portions into contact while the rod stock isadvanced between the rolls and reduced thereby in dimension, means forcontrolling the magnitude of said pressure force, said pressure forcecontrolling means reducing the pressure force when there is no stockbetween the rolls and thereby reducing the possibility of excessive wearand cracking of the rolls.
 6. A rolling stand as defined in claim 5wherein each of said rolls has shaft portions projecting from theopposite ends thereof, roller bearing housings associated with eachshaft portion and rEceiving each of said shaft portions, and said meansfor establishing a torque-transmitting relationship between said furthersurface portions comprising means associated with said roller bearinghousings for urging said housings together.
 7. A rolling stand asdefined in claim 6 wherein said means for establishing saidtorque-transmitting relationship comprises rod means which extendsthrough passages in said roller bearing housings and which is slidablyreceived in said passages, and hydraulic means associated with said rodmeans, said hydraulic means including first and second chamber portions,said first chamber portion on an increase in pressure therein relativeto the pressure in said second chamber portion effecting movement ofsaid roller bearing housing apart to thereby move said rollers apart andsaid second chamber portion upon a pressure increase relative to thepressure in said first chamber portion therein urging said rollerstogether to increase the pressure relationship between saidtorque-transmitting surfaces of the rollers.
 8. A method of rolling barsteel or wire rod stock comprising the steps of providing first andsecond rolls which define a nip therebetween, advancing stock betweensurface portions of the rolls to reduce the cross section of the stock,positively driving one of said rolls from an external source, drivingthe other of said rolls due to surface pressure engagement between saidrolls establishing said torque-transmitting pressure relationshipbetween said rolls to drive the second roll from the first roll due onlyto said torque-transmitting relationship while the rod stock is beingadvanced through the rolls, and reducing said torque-transmittingpressure when there is no stock between the rolls.
 9. A method ofrolling as defined in claim 8 further including the step of varying thepressure relationship between the rolls for different rollingoperations, and removing the pressure relationship entirely and movingone of said rolls relative to the other of the rolls when the rollingoperation is completed.